1. Field of the Invention
The present invention generally relates to a method and apparatus for stabilization of an image, and more particularly to a video signal processing circuit and method used in performing vibration correction for an image on a display device.
2. Description of the Related Art
In recent years, electronic equipment including a display (e.g., such as a palmtop/laptop computer display, video games, televisions, display monitors, etc.) have become miniaturized and hence portable so that such equipment can be taken virtually anywhere and such equipment can be operated in virtually any environment including moving vehicles, boats, airplanes, etc.
In a moving vehicle such as an automobile, a disadvantage of viewing, for example, a laptop computer's display, such as for the IBM Thinkpad.RTM., is the eye strain caused by vibrations and jitter of the vehicle. Further, the observer cannot easily follow the image during such vibration/jitter of the vehicle.
Additionally, there are certain human diseases which manifest themselves in tremors or palsy which induce movement in the device that make it nearly impossible for the handicapped user to view the display. Other devices that have the same disadvantage include Cathode Ray Tubes (CRT), Personal Digital Assistants (PDA), and Smart Cards.
It is noted that conventional recording system exist for correcting video camera vibrations. However, such a correction mechanism have been incorporated into image recording devices, and have not been found in image display devices and more particularly portable image display devices.
In a conventional system for motion compensation in a video recording device, the system identifies in the digitally recorded picture those elements with distinguishing characteristics. For example, objects with clean sharp edges and high contrast. Then, if those elements move, processing circuitry digitally shifts the picture to compensate for the motion.
However, this system fails to incorporate motion sensing devices (such as accelerometers) for motion compensation in a video display device or in an image other than one which is recorded. Hence, the device (e.g., video recorder) is aware of its coordinates, and extracts coordinates information from the recorded picture. Such a system is not applicable to a display undergoing physical/mechanical vibration and jitter.
Such a system for a video recording device is cannot be incorporated in a display device unless the display device is equipped with a fixed camera that can record the display device's motion and infer from the recorded image the displacement in two dimensions. Hitherto, the invention such a technique has not been performed in which motion is deduced directly for a display device being physically vibrated or moved. Additionally, such a system is very costly to manufacture.